13
IOM Manual: IOM-0000-CST IOM
Series CST: Submersible Turbine
01/01/2018 - Edition 1A
www.cps-pumps.com
• Incorrect pump rotation (3 phase only)
• Improper voltage
• Sand locked pump
• Improper cable size or leak in cable
• Mechanical damage
In any case, the problem must be corrected before the pump can
be operated.
On three phase units if water does not appear within one min-
ute (deeper settings may require approximately one half minute
per 100 ft. setting) the motor may be running backwards. Stop
the pump and interchange any two of the three cable connec-
tions. If there is any doubt about the proper rotation, run the
motor in one direction and then the other. The rotation that
gives the highest pressure and flow is always the correct one.
Check the voltage. The voltage when the pump is running
should be within 5% of the pump motor nameplate voltage.
Open the throttle valve. If a flow meter is available, open the
throttle valve to rated flow of the pump. If sand appears in the
water, throttle the pump at approximately 80% of full flow until
the sand clears. If excessive noise develops, pressure fluctuates,
or water appears foamy white, the pump is probably cavitating
and the flow should be throttled until the noise diminishes, the
pressure remains steady, and the water is clear.
On three phase units check for current unbalance. Details of
the current unbalance test are given in ELECTRICAL TESTS
on page 18. THE MAXIMUM ALLOWABLE CURRENT
UNBALANCE IS 5%. If the current unbalance exceeds 5% af-
ter rolling the leads and connecting them for the lowest unbal-
ance, the pump should be stopped and corrective action taken.
Current unbalance in excess of 5% can be expected to cause ex-
cessive heating in the motor and premature failure. Operation
with a current unbalance in excess of 5% will void the warranty.
After the unit is operating properly, a performance test should
be considered. See ROUTINE OPERATION AND MAIN-
TENANCE on page 15. If a performance test is conducted
when the pump is new, subsequent tests can be used to deter-
mine the degree of wear or deterioration of the pump without
removing it from the well.
After the unit has been in operation for approximately one
week, perform the routine tests listed in ROUTINE OPERA-
TION AND MAINTENANCE on page 13.
ROUTINE OPERATION AND
MAINTENANCE
A submersible pump, properly installed in a clean well, will run
for a long period of time with a minimum of attention. How-
ever, conditions are not always ideal and can change for the
worse in the course of time. Submersible pumps usually run
unattended and automatic control devices are used to stop and
start the unit and to protect it from abnormal conditions such as
overloads, line faults, etc. It is important that these automatic
devices be adjusted properly and maintained in good working
condition. Failure of an automatic control can easily cause the
failure of a pump that is in excellent condition. Unfortunately
these protective devices may not protect the installation against
all of the hazards that may be encountered.
In order to assure that potential problems are identified and
corrected as soon as possible, a program for regular inspection
and testing of the unit should be established. The frequency of
inspection and testing will vary depending on the complexity of
the controls, the consequences of a failure, the cost of making
the inspections and tests, the age and condition of the unit,
the results of previous inspections and tests, and the operating
philosophy of the owner.
ROUTINE INSPECTIONS
On a periodic basis, the unit should be given a quick inspection.
The inspection should include the following:
• Check for any obviously abnormal conditions such as
gross leakage or gross damage.
• Check that the unit is not making excessive noise.
Check the electric panel for alarms, blown fuses, etc.
• Check the electrical system for signs of overheating
or other abnormal conditions.
Any problems noted should be carefully investigated and cor-
rected immediately.
ROUTINE TESTING
The following tests should be performed on a periodic basis and
at any time the pump is started up after a prolonged shutdown.
All test readings should be recorded so that they can be used for
comparison. Gradual changes can indicate a gradual deterio-
ration. Large changes can indicate rapid deterioration with a
potential for sudden failure in the near future.
• Check the resistance between the drop cable conduc-
tor and ground. See FIGURE 5.
• Measure the resistance of the drop cable and motor
windings. See ELECTRICAL TESTS on page 18.
• Measure the voltage and the current. Compare the
readings with previous readings. If either the voltage
or the current has changed substantially, check the cur-
rent unbalance. See ELECTRICAL TESTS on page
18. Excessive current is an indication of a problem
somewhere in the system which should be corrected
immediately.
• Measure the water level in the well. A drop in the
